1. Field of the Invention
The present invention relates to a weather strip for a motor vehicle and, more particularly, to a weather strip to be attached to a door opening portion along a side of a roof of a motor vehicle.
2. Description of Related Art
In a hardtop-type motor vehicle shown in FIG. 1, a weather strip 10 is attached to a door opening portion 12 along a side of a roof 14, which ranges from a front pillar 16 to a rear pillar 18. In FIG. 1, reference numeral 20 designates a door glass.
Generally, the weather strip of this type is composed of an extruded body of an elastic material such as rubber or thermoplastic elastomer, and includes a thick base portion and a tubular seal portion which has a seal wall defining a tubular space. Publication of unexamined Japanese patent application No. Hei5-213119 discloses one example of the weather strip of this type. In this example, a retainer is provided along the door opening portion, and the weather strip is attached by fitting the thick base portion in the retainer.
It has been demanded to reduce the protrusion height of the weather strip from the door opening portion, thereby improving the view from a vehicle window. In order to respond to this demand, as shown in FIG. 2 and as disclosed in the above publication, there has been proposed a weather strip 10A which has a tubular configuration, and is entirely composed of a sponge material. Upon attaching, a bottom portion 22 of the weather strip 10A is bonded to a retainer 24 provided along the door opening portion 12 with a double-sided adhesive tape 26.
The protrusion height of the weather strip 10A can be reduced, as compared to the conventional weather strip of which a thick base portion is fitted in the retainer. The weather strip 10A, however, exhibits the problem that, upon bonding, the bottom portion 22 may be offset from a predetermined bonding position, whereby the weather strip 10A may be attached in a meandering state, and a resultant seal between the weather strip 10A and the door opening portion 12 becomes instable.
In order to ensure the attaching stability of the weather strip, as shown in FIG. 3, there has been proposed another weather strip 10B which has a tubular configuration, and includes a bottom portion 28 composed of a solid rubber, and a seal wall 30 composed of a sponge rubber. A groove 34 is formed in the bottom portion 28. A roof-side moulding 32 is secured to the door opening portion 12. A base plate 38 of the roof-side moulding 32 has a projection 36 along an inside end thereof. The weather strip 10B is attached to the door opening portion 12 by fitting the groove 34 of the bottom portion 28 onto the projection 36 (Publication of unexamined Japanese patent application No. Hei7-291056).
With this attaching structure, the weather strip 10B can be positioned and attached in a predetermined attaching position. In order to further improve the attaching stability of the weather strip 10B, the bottom portion 28 may be bonded to the base plate 38 with a double-sided adhesive tape 40. In this case, before bonding the bottom portion 28, the groove 34 is previously positioned onto the projection 36 of the roof side moulding 32. Accordingly, the weather strip 10B can be attached in a predetermined position of the door opening portion 12 more accurately.
The weather strip 10B, however, exhibits the following problem. Where the protrusion height of the weather strip 10B is reduced to improve the view from a vehicle window, the widthwise length of the seal wall 30 of which side ends are respectively connected to side ends of the bottom portion 28 becomes short. When the door glass 20 is raised, and a peripheral edge thereof pushes the short seal wall 30 upwardly, a tension force is generated therein. Consequently, as shown in FIG. 4, a space S is formed between each side of a peripheral edge of the door glass 20 and the seal wall 30 so that, as shown by solid lines, the seal wall 30 does not sufficiently wrap the peripheral edge of the door glass 20. This results in the contacting area of the seal wall 30 against the peripheral edge of the door glass 20 decreasing, and the water-stopping properties and sound-insulating properties degrading.